This invention relates to a poured concrete wall form panel and, more particularly, to a method of making such a panel.
It is well known in the art to use prefabricated and reusable panel units to construct a wall form for a poured concrete wall. Typically, each panel has a marginal frame welded to an projecting rearwardly from a back face of the panel to include a flange along the spaced side edges of the panel. The flanges are adapted to be positioned in face-to-face relationship with the flange of an adjacent panel to construct a concrete wall form. Holes in the flanges of the adjacent panels can be aligned to receive therethrough the shank of a pin or a bolt. A pair of spaced concrete wall forms are assembled and liquid concrete is poured between the wall forms and allowed to cure or harden thereby forming a poured concrete wall. Once the wall has cured, the concrete wall forms and associated hardware are disassembled for transportation to another job site and reuse.
In the construction of a concrete wall form, a large quantity of panels is necessary to construct the appropriately sized and configured poured concrete wall. Typically, the individual panels used to construct the wall forms are 7' or 8' in height and 2' or more in width. Panels which are less than 12" in width are typically called fillers. It will be appreciated that a variety of panel sizes, configuration and dimensions is required to appropriately construct a wall form for the various poured concrete wall configurations which are required in modern construction designs.
Currently, wall form panels are manufactured by welding a perimeter frame to the rear face of a generally planar panel. The welded connection between what becomes the rearwardly extending flanges on the wall form panels and the front planar face of the panel is subjected to very high stresses and hydrodynamic forces as a result of the poured concrete between the wall forms. Therefore, the welded connection between the rearwardly extending frames/flanges and the panels weaken or fail in use. The stresses are particularly accentuated along the side edge flanges of the wall form panel because that is the location of the connection between the adjacent panels and the concentration of the forces exerted by the poured concrete on the wall panels.
The concrete poured between the assembled forms acts substantially like a fluid and delivers significant hydrostatic pressures to the wall panels he forms. Typically, the compressive load on a concrete form 8' high can easily reach 1,000 to 1,200 pounds per square foot. The panel, connection hardware and assembled wall form must be able to withstand these pressures without buckling, deformation or failure.
For this reason, known panels can be quite heavy, typically each weighing about 90 pounds or more. Usually a single worker manipulates the panels and moves them around on the job site. Therefore, a lighter weight panel would not only reduce material and shipping costs, but increase labor productivity while minimizing potential injuries to the workers who handle the panels. However, lighter panels typically suffer from the problem of providing insufficient strength or structural integrity to the assembled wall form.
One solution to these problems with respect to wall form panels is disclosed in U.S. Pat. No. 5,651,910 issued to Myers et al. on a concrete wall form and tie system, the disclosure of which is incorporated herein by reference in its entirety.